Process for depositing microcapsules into multifilament yarn and the products produced

ABSTRACT

The invention is directed to a process for depositing additives into a yarn having multi-filaments comprising steps of; separating the multi-filaments of the yarn into individual filaments while winding the yarn; injecting the additive onto the individual filaments; and promoting the individual filaments of the yarn to close up one against the other whereby the additive are entrapped within the multi-filaments. The invention also concerns an apparatus for depositing microcapsules into a multi-filaments of a yarn and the multifilament yarn produced.

RELATED APPLICATIONS

The present application claims priority on U.S. provisional applicationNo. 60/574,942 filed on May 28, 2004, the contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a process for providing additives toyarn made of multifilament textiles.

DESCRIPTION OF THE PRIOR ART

Micro-encapsulation has been used in the textile industry since theearly 1990's. Many textile manufacturers are looking into the use ofmicrocapsules to functionalize their products by giving textiles: adurable scent; a means for applying a cosmetic, such as a body lotion,or a pharmaceutical product.

Microcapsules applied to textile materials impart characteristics whichdepend on the nature of the active substances present inside themicrocapsules. The large number and variety of active substance that canbe used is further proof of the usefulness of the micro-encapsulationtechnique in the fabrication of different textiles which have manyapplications.

Microcapsules have been applied to the textile webs (woven, knitted andno woven fabrics), fibers, and monofilaments or multifilament yarns. Themajority of described techniques for applying of microcapsules to thetextiles is designated for the webs finishing.

Impregnation is one method of web/fabric finishing. The web is placed ina treatment bath, such as a “pad” machine, which contains both chargedmicrocapsules and a binder. Optionally products include: dispersingagents; pressure absorbing agents; softening agents and surfactantsalone or in combination may also be added. The treated fabric must bedried and/or cured (soaking process); or squeezed and dried and/or cured(padding process). The binders anchor the microcapsules to the fabric.Suitable binders for microcapsule finishing include: polymeric melaminecompounds; polymeric glyoxal compounds; polymeric silicone compounds;polyalkylene glycols; poly(meth)acrylates; polymeric fluorocarbons andepichlorohydrin-crosslinked polyamidoamines. The surfactants present inthe bath facilitate interactions between the components of the bath andthe fabrics and improve the “fabric hand” after treatment. Thedrying/curing processes are necessary for water/solvent evaporation fromthe treated fabric and in some cases for activating some bindersrequiring higher temperature to bind the web/fabric.

The impregnation method (padding or soaking) is described in U.S. Pat.No. 4,882,220 where microcapsules containing a fragrance are applied toa fabric by soaking, padding and printing processes. In U.S. PatentApplication 2002/0166628, the soaking method is disclosed. CanadianPatent Application 2,483,279 describes applying microcapsules by soakingand padding. Finishing of fabrics with microcapsules containingskin-conditioning agents by soaking, padding, coating, spraying andprinting method is described in U.S. Pat. No. 5,232,769. Japan Patentdocument JP 11012953 describes the method for obtaining ananti-inflammatory and/or analgesic textile material by textile finishingwith microcapsules containing a biological active agent.

Microcapsules have also been applied to textile fabrics using a coatingprocess. The fabric to be treated is exposed to microcapsules coatedwith the binder in a coating machine. Here any excess of coatedmicrocapsules is eliminated from the fabric, for example, by a knifesystem. The coated fabric is then dried and/or cured. This method isdescribed in U.S. Pat. No. 3,479,811, where expandable micro-spheres areincorporated on the surface of the fabric by the coating process.Canadian Patent 1240883 describes a coating process for microcapsulescontaining thermo chromic pigments. The coating method to functionalizefabric by microcapsules is also described in Korean Patents KR2002056779 and KR 2001069654. Electrically conductive andelectromagnetic radiation absorptive fabric was obtained bymicrocapsules coating described in U.S. Patent Application 2004/0212.

Other methods of applying microcapsules to textile fabrics include:spraying described in International Patent WO 00/05446, in Korean PatentKR 2002082692 and in two Japan Patents JP2000178873 and JP02200602;printing described in European patent EP 1231319 printing allows onlyselected areas of textile fabric to be functionalized; and doping aspinning solution with the microcapsules and extruding the fibersalready finished, as described in U.S. Pat. No. 3,852,401.

All these methods for applying microcapsules on yarns require anadditional treatment step which may be long and laborious. Thus, thereis a need for a process for applying microcapsules to yarn “on-line”during a normal finishing process of yarns.

Furthermore with the yarn treatments discussed, only the yarn surface iscoated by binder and microcapsules. This gives the fabric a “rough hand”which is not acceptable for many products like, especially productswhich will be in contact with the body. Thus, there is also a need formicrocapsules finishing yarns which can be used which have a “fabrichand” which is soft final products.

SUMMARY OF THE INVENTION

In one aspect of the invention there is a process for depositingadditives into a yarn having multi-filaments comprising steps of;separating the multi-filaments of the yarn into individual filamentswhile winding the yarn; injecting the additive onto the individualfilaments; and promoting the individual filaments of the yarn to closeup one against the other, whereby the additives are entrapped within themulti-filaments.

According to another aspect of the invention there is an apparatus fordepositing microcapsules into a yarn having a plurality of filaments,the apparatus comprising; a supply spool, a take-up spool winding theyarn in a first direction between the supply spool and the take-upspool, a means for separating the yarn at, at least one separating pointdisposed between the supply spool and the take-up spool, the means forseparating the yarn thereby exposing the filaments, and at least onenozzle proximate the separating point, the at least one nozzle injectinga liquid onto the filaments in a second direction transverse the firstdirection, the liquid having a the microcapsules suspended therein andthereby injecting the microcapsules.

According to yet another aspect of the invention there is amultifilament yarn having a cross sectional perimeter, the yarncomprising: individual filaments interconnected together to produce theyarn; and microcapsules having a range of diameter of 0.1 to 200 μm onthe individual filaments within the perimeter of the yarn.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention will becomeapparent from the following detailed description, taken in combinationwith the appended drawings, in which:

FIG. 1. is a schematic representation of the process steps of anembodiment of the present invention where Partially Oriented Yarn (POY)is used as a starting material and the aspect of the filaments of thePOY during processing is represented;

FIG. 2 is a schematic representation of the process of anotherembodiment of the present invention multiple Partially Oriented Yarns(POYs) are the starting material and produce a multifilament yarn whichis textured by an air jet device and one POY being overfed onto theother;

FIG. 3 is a schematic representation of a system of injection of adispersion of the microcapsule according to one embodiment of thepresent invention;

FIG. 4 is a cross section of a device for the deposition of theadditives according to one embodiment of the present invention; and

FIG. 5 is a micrograph of microcapsules on the filaments within a DrawTextured Yarn of one embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The invention is applicable to manmade textiles that include but are notlimited to: polyesters, polyamides (nylons), aramids, polypropylene, andother synthetic and/or artificial multifilament yarns. Multifilamentyarns are understood to be composed of a plurality of filaments.

The following terms are included to clarify the definition of the termsfound in the application.

The term yarn is defined as a continuous bundle of textile fibers,filaments or materials in a form suitable for intertwining to produce atextile fabric. A multi-filament yarn has two or more individualfilaments intertwined. There are many forms of yarn such as; spun yarnwhere a number of fibers are twisted together; zero-twist yarn, wherethe filaments are laid together without any twist; twist yarn whichincludes a number of filaments with a twist.

Winding is understood to mean a process of transferring yarn or threadfrom one type of package to another to facilitate subsequent processing.The package or spool is understood as the forms for winding yarn, mostof these packages are flangeless to allow high speed of unwinding.

There are two types of winders precision and drum winders. Precisionwinders are used for the most part with filament yarns, they include acam driven traverse and an oscillating motor moving a traverse, thatsynchronize the spindle to produce packages with a wounddiamond-pattern. Drum winders, including propeller type systems, areused principally for spun yarn, where a frictional contact drives thepackage.

The term texturing is understood as a process that produces randomloops, crimping, or other operation which increases the texture of ayarn. These operations also increase insulation value, warmth andabsorption of the yarn, and provides a different texture to the surfaceof a yarn. The present process of deposition of microcapsules requiresthe application of the microcapsules onto a textured yarn. Many types oftextured yarns are known to the skilled practitioner they include: DrawTexture Yarn (DTY) and Air Textured Yarn (ATY). As will be described,non-textured or flat yarns may be used as a starting material.

Reference is made to a textile winding machine which is understood toinclude: a winder; a texturing machine, or a twister. A preferredembodiment of the texturing machine is a false twist texturing machineor an air texturing machine.

The textile handling machines listed above is not limitative and theskilled practitioner would understand that other textile windingmachines may be used. Textile handling or processing includes: spinning;plying; twisting; texturing and coning. Textile processing includes manymechanical operations used to translate a textile fiber or yarn to afabric or other textile material and would be understood by the skilledpractitioner.

Micro-encapsulation is a technique of enclosing chemically,physico-chemically or biologically reactive material in tinymicrocapsules from which the material can be released under particularconditions.

A microcapsule is composed of an outer wall or shell comprising anatural, semi-synthetic or synthetic, high molecular weight materialsuch as gelatin; Arabic gum; agar agar; alginic acid and salts thereof;fatty acids; cetyl alcohol; collagen; chitosan; lecithins; albumin;starch; dextran; polypeptides; cellulose and chemically modifiedcellulose; polyacrylates; polyvinyl alcohol; polyvinyl pyrrolidone;polyurethane; polyolefin; polyamide; an aminoplast; polyester;polysaccharide; silicone resins; epoxy resins and formaldehyde resins.In a preferred embodiment the aminoplast is a melamine. Microcapsuleshave a particle diameter in the range from to 0.1 to 1000 μm, preferablybetween 0.1 to 200 μm, and most preferably 0.5 to 20 μm.

The process of the present invention is continuous, rapid, andsubstantially dry, it is executed over a short period of time, of aslittle as, 1/10 to 1 sec, while the classic soaking process may requirefrom 2 to 3 hours, furthermore the dry conditions (dry yarn) providesgood fixation of microcapsules. The process of the present invention isapplicable to many kinds of yarn, allows for flexibility by allowing forthe use of short runs of yarn, as well as, lower quantities of activelycharged microcapsules to achieve the target activity of final product.Like all other yarns, the yarn of the present invention has a length anda perimeter. However, with the yarn produced by the process of thepresent invention, microcapsules are found within the perimeter of theyarn, not only on the perimeter, or outer surface, as with someprocesses. The present process is eco-friendly as active ingredients arerecycled in the system and chemical losses are minimized, thus alsoimproving cost effectiveness. The yarns finished by the process ofpresent invention have a substantially uniform microcapsulesdistribution. The textiles webs fabricated from yarns of the presentinvention have a “soft hand” and are applicable to textile webs whichgradually release encapsulated active substances and which may be inpermanent contact with wearer's skin and body.

FIG. 1 represents one embodiment of the process of the present inventionfor producing a multifilament Draw Textured Yarn (DTY) includingdeposited microcapsules according to the present invention in a textilewinder. The process steps, as well as the schematic nature of thefilaments of the yarn during the processing is represented in FIG. 1.The direction of movement of the yarn during processing is indicated bythe arrow 2. A supply spool 10 of a multi-filament partially orientedyarn (POY) 12 is fed from the spool 10 to a first shaft 20 also calledan input feeding shaft or roll, rotating at a given speed. From thisshaft 20 the yarn is fed to a second shaft or roll 60, which turns at ahigher speed than the first shaft 20. Thus, the yarn 12 issimultaneously drawn, its length is increased and diameter diminishedand twisted. The yarn 12 is twisted after the first shaft 20 by afriction device, such as a set of spindles or friction discs 50 whichproduce a twisted yarn 22. The yarn 22 enters a heater 30 where itstemperature is increased so that the yarn 22 is thermo-fixed (130° C. to500° C.). The heater 30 is followed immediately by a cooling zone 40which may be at room temperature or may be cooled below roomtemperature. The cooler 40 has a smooth curved surface which facilitatesthe cooling and reduces the likelihood of breaking very fine filamentsof yarn. The yarn 52 leaving the friction discs 50 may in some cases bestraightened as represented in the FIG. 1.

The tension between the second shaft 60 and the first shaft 20 caused bythe greater speed of the second shaft 60 causes the filaments of theyarn 22 to be elongated while heated. The tension of the drawn yarn 62leaving the second shaft 60 is lower due to the lower speed of shaft 80(or the “2 bis” roll) in relation to shaft 60.

This reduction in speed is permissible because there is a reduction inthe length of the yarn produced by the bulking of the yarn and itsstretch behaviour. The yarn 62 has become somewhat crimped. Thus theoperation of twisting and heating the yarn produces curling of thefilaments lower than that of shaft 60, permitting retraction and bulkingof the entire multifilament yarn. It should be noted that this reductionin tension or un-tensioning, causes the filaments in the yarn toseparate to some degree. Therefore, the speed of a third shaft or“2-bis” roll, 80 which rotates at a marginally lower velocity than thesecond shaft 60, is related to the percentage of reduction of overalllength of the yarn. Thus the shafts 60 and 80 serve as a means ofseparating the yarn into individual and exposed filaments.

The yarn travels or winds through an opening or passage extendingthrough the body of device 70 in the direction indicated by the arrow 2.The filament in yarn 62 are separated as well as, possibly interlaced orintermingled in the device 70, where in a preferred embodiment there isan air jet 72. The yarn 62 enters the device 70 where the air jet 72 (ata pressure as much as 100 psi) is directed at the yarn 62 in aperpendicular or nearly perpendicular direction with respect to the ofmovement of the yarn 2. The yarn 62 comes into contact with air vorticesproduced by the air jet 72 which act as a means of separating of thefilaments of the yarn 62 in a preferred embodiment. The air jet 72enters the device 70, through an aperture transverse to the openingthrough the device 70. As the filaments move out of the jet 72 due tothe movement of the yarn, they re-orient back onto each other, mayproduce braids or knots at regular intervals within the yarn 76. Theskilled practitioner would understand that a gas jet, such as the airjet 72, are produced by a gas or fluid passing through an aperture, ahole, or a nozzle, and possibly via other devices such as a valve, whichproduces a very high velocity gas/fluid stream. The skilled practitionerwould understand that the air in the air jet 72 may be replaced withanother suitable gas or combination of gases such as an inert gas likenitrogen, helium, neon or argon if required. In a preferred embodimentthe air/gas jet 72 may also be heated.

The device 70 includes a hole or nozzle for a stream 74 through whichsuspended microcapsules are injected into the device 70 at the pointclose to where the filaments have been separated from one another, intoindividual filaments, while winding through the device 70. This nozzleis located along the winding path of the yarn, and is located proximateto a point where the filaments have been separated. In a preferredembodiment the nozzle producing the liquid jet 74 is located downstream,with respect to the direction of travel of the yarn 2, of this yarnseparating point. In a preferred embodiment, the microcapsules liquidjet 74 leaves a nozzle intersecting the yarn winding opening, theintersection of liquid nozzle and yarn winding opening is substantiallyopposite and/or slightly downstream of an aperture for an air jet 72.The liquid nozzle and the aperture may both be transverse to the yarnwinding opening through the device 70. In a preferred embodiment theaperture for the jet 72 and the nozzle for the liquid stream 74 areperpendicular to the wall of the opening of the device. The stream orspray 74 of microcapsules will be injected into and adhere to theseparated individual filaments and coat the filament surfaces. Inanother preferred embodiment, there are two air jets and two liquid jetsand each air and liquid jet is in close proximity to one another and aresituated along the wall of opening through the device 70. Furthermore,the orientation of the nozzles along the wall opening may be directed atthe winding yarn so that the jet makes a perpendicular angle to thedirection of travel of the yarn 2. The angle made between the directionof the liquid jet 74, the air jet 72 when either jet leaves the nozzlein a substantially straight line, and the direction of travel may varyby 30° from the perpendicular and as much as 45° from the perpendicular.

As the filament continues to wind through the jet device 70 it leavesthe vortices produced by the air jet 72 and the filaments close up uponthemselves thus sealing the microcapsules within the yarn. This braided,interlaced or intermingled and textured yarn 76 thus produced, includesmicrocapsules within the structure, as well as on the external surfacesof the yarn 76. The microcapsules are also found within the narrowhollows of the intermingled or entangled filaments. Because themicrocapsules make it into these grooves or channels of the specificfilaments of yarn, the yarn is expected to retain the microcapsules andtherefore the properties of the materials within the microcapsules for alonger period of time, than in processes where the yarn is coated onlyon the surface. FIG. 5 is a electro-micrograph of a yarn where theindividual filaments include microcapsules.

The additives may be injected into the yarn directly after the shaft 60without the aid of an air jet 72. But the use of an air jet improves theprocess by separating the individual filaments of 52 before insertingthe microcapsules. The jet 72 separates the filaments to a greaterextent than with only un-tensioning due to the effects of the operationof the shafts alone, and is thus a preferred mode of operation for thisinvention.

Throughout the disclosure the words; additive, microcapsule andnanocapsule are used interchangeably, each of which can have a singleconstituent or multiple components. The additives are preferablymicrocapsules in a range of diameter from 0.1 to 1000 μm, preferablybetween 0.1 to 200 μm, and most preferably 0.5 to 20 μm, where themicrocapsules have an outer wall and a central core. The wall is adaptedto bind to the filaments. In a preferred embodiment the outer wall ofthe microcapsule fuses with the individual filament by the action ofheat and/or with the binder. The central core of the complete particleor microcapsule, may include a substance or material which ischemically, physico-chemically or biologically active or simplycosmetic. These materials may be topical skin lotions or medicines.

The chemically, physico-chemically or biologically active materialenclosed inside of microcapsule may include the following types ofsubstances: bioactive agents, drugs and pharmaceuticals; enzymes; dyesand pigments; fragrances; moisturizing agents; bleaching agents;depilatory agents; UV-block agents; softening agents; elasticityimproving agents; flame-, moth-, crease- and soil-proofing agents; waterrepellent agents; anti-shrinking agents; cross-linking agents; magneticparticles; thermochromic, photochromic, electrochromic, piezorochromic,solvatechromic, carsolchromic materials; insects repellents; pesticides;static electricity-controlling or reducing agents; electricallyconductive materials; radar-absorbing materials; reflecting particles;heat-absorbing and/or heat-releasing phase change agents;decontamination agents; zeolites; activated carbon; and combinations ofthese substances.

The yarn 76 continues to the third shaft 80 and the fourth shaft (alsobe called the delivery or nip roll), 100. In between the two rolls 80,100 a heater 90 may be included. The optional heater 90, may evaporateany solvents or aqueous component injected with the microcapsulessuspension and also helps to further bind the microcapsules to thefilaments. The fourth set of shafts 100, serves to control overfeed inthe temperature setting zone, before the yarn 102 is drawn or wound ontothe take-up spool 112 with the aid of take-up shaft 110.

It is noted that many variations of location for the device 70 and theinjection of microcapsules is possible. The device 70 has been locateddirectly after the shaft 60 without the inclusion of an air jet, as wellas, directly after the second heater 90 and before the nip roll 100.Microcapsules have successfully been applied and inserted into themulti-filaments of the yarn at various locations.

The deposition process of the present invention requires that the yarnbe textured before the separation and deposition occurs. However, thestarting yarns may be textured, immediately upstream of the process ofthe present invention, and this is described in FIG. 2. Thus PartiallyOriented Yarn (POY), Fully Oriented Yarn (FOY). and Low Oriented Yarn(LOY) and combinations thereof, which are not textured yarns may serveas starting products but they must be textured before the microcapsulesare deposited. In the mode proposed in FIG. 2, more than one spool ofPOY, FOY, LOY or combinations thereof is fed in a winding machine. EachPOY or other yarn, passes over a heater into an air jet device. FIG. 2is an option of texturizing POY into a multi-filament yarn before thedeposition of the additive/microcapsule. The direction of the movementof the yarn in FIG. 2 is indicated by the arrow number 3. By the processof this invention spools (150, 160) feed POY onto feed shafts (170, 180)the filaments are drawn by a second set of shafts (220, 230) at agreater speed through a similar series of steps which include a heatingstep (190, 200) with the POY. These POY yarns can be further texturedsuch that the feed rate of the yarns from the second shafts 220 and 230are different in the order of −10% to +200% thus the yarn 231 leavingthe shaft 230 may be fed at a speed as much as 200% greater than theyarn 221 leaving the shaft 220. The yarn 221 is called the core yarnwhile the yarn 231 is called the effect yarn in entering the air jetdevice 240 the air jet 242 has a tendency of enveloping the effect yarn231 over the core yarn 221, to give a multiplicity of loops and thus thePOY yarn which was only partially oriented is now a multi-filament yarnready to have additives incorporated by the process of the presentinvention through the hole for jet 264.

Due to the high level of looping of the effect yarn 231 around the coreyarn 221, the type of process arrangement often includes two stabilizingrollers 250 and 270, which reduce and stabilize the yarn produced to amore uniform thickness. In a preferred embodiment the microcapsule jetdevice 260, optionally including another air jet 262, is placed betweenthe two sets of stabilizing rollers 250 and 270. As in previous examplesthe liquid jet 264 incorporates additives within the yarn, withindividual filaments separated by un-tensioning of the yarn or by theaction of an air jet.

The multi-filament yarn leaving the jet device 260 and roller 270,including microcapsules may once again be heated to evaporate theaqueous phase and so as to further adhere the microcapsules to the nowmulti-filament texturized yarn in heater 280. The heater 280 is betweenrolls 270 and 290. From the roll 290, the yarn is wound onto the take-upspool with the aid of take-up shaft. The take-up spool and shaft are notillustrated in FIG. 2. Thus various methods of generating the texturedmicro-filament yarn required for the incorporation of microcapsules bythe process of this invention are possible and would be clear to theskilled practitioner, and be used for the deposition of additives by theprocess of the present invention.

The skilled practitioner would also understand that other types of yarnusing similar arrangements of textile handling equipment may generatemultifilament textured yarn.

Preparation of the Suspension of Microcapsules

FIG. 3 represents a tank 300 which includes a mechanically ormagnetically driven agitator 310 where the suspension of microcapsulesin aqueous phase is prepared. The tank 300 may include a means 320 whichheat the suspension of particles in a controlled manner. The suspensionis re-circulated from the tank 300 by means of a pump 330. The pump 330is selected from the group of pumps which are designed to minimize theshear and thus the breakage of microcapsules in suspension. The types ofpumps applicable are selected from the group consisting of peristaltic,diaphragm, progressing cavity, and centrifugal disc pumps. The skilledpractitioner would understand that this group of pumps is not limitativeand other pumps minimizing the shearing of microcapsules may beemployed. The suspension is circulated in a piping or tubing system 332to the typical jet device 370 where the multi-filament yarn 360 will beintermingled by the action of the air jet 372 and coated by the actionof the jet 374 of microcapsules. The suspension is not completelyconsumed by spraying onto the filaments and is collected in a vessel 380for re-circulation by pump 339 back to the original reservoir 300.

The suspension of microcapsules may contain components that have atendency to block jet 374 which requires periodic cleaning orde-blocking of the hole through which liquid jet passes during operationby periodic maintenance. This periodic cleaning may be performed by amechanical device or through the selection of self-cleaning jets.

FIG. 4 illustrates a cross sectional view of a preferred embodiment ofthe present device 470 used to deposit additives such as microcapsulesand nano-capsules into the filaments of a textured yarn. The deviceincludes a body 400 defining a central opening or hole 405 which passesthrough the device 470, in a preferred embodiment the hole iscylindrical. The hole 405 is adapted to allow: the passage of texturedyarn 62 at high speed into and through the opening 405, and the exit ofthe intermingled yarn 76 at the outlet end of the opening 405. Thedirection of the movement of the yarn 62 through the device 470 isindicated by the arrow 4.

The wall of opening 405 is intersected by at least one hole for a liquidjet 474, which due to an un-tensioning caused either by the slightreduction of speed through the device, or by the inclusion in apreferred embodiment of an aperture for an gas or air jet 472 which willopen the multifilament and allow the deposition of additives within theindividual filaments of the yarn 62. Upon leaving the vortices of theair jet 472 the individual filaments of the yarn will have a tendency toclose up one against the other, but the winding of the yarn through therolls will further promote this closing of the individual filaments ofthe yarn. FIG. 4 represents a preferred embodiment which includes twoliquid holes or nozzles 473, 475, which produce two liquid sprays (orjets) 474, 476. The number and placement of liquid holes can beincreased or decreased depending on the speed of the yarn through thedevice 470, and would be understood by a skilled practitioner. In apreferred embodiment the hole(s) 473, (475), are liquid nozzle(s) andare located opposite an aperture 471 for the air jet 472 along the wallof the opening. The air jet hole 471 and the air jet 472 are once againused to separate the filaments of the yarn. This embodiment of thedevice has mechanical means for cleaning the liquid nozzles by a systemof plungers 491 and 493 which scrap any build-up from the top of theliquid holes 473, 475. Arrow 495 represents the direction of themovement of the plungers 491, 493. In FIG. 4, one of the plungers 491 isin a retracted position, while plunger 493 is in an extended positionremoving any deposits of additives which may have built up in the hole475. Other means for the cleaning of the nozzles 473, 475 can beenvisaged and include the redirection or the addition of a the highpressure air jet towards the top of the liquid jets 473, 475. Many suchalternatives are available and known to the skilled practitioner. InFIG. 4 the deposited microcapsules have been represented by varyingsized triangles, indicating the incorporation of microcapsules on thesurface and within the yarn 76.

The excess liquid from the jets 474, 476 passes out the end of thedevice at the outlet end of the device 470. This excess is collected ina tank or container 480 and re-circulated back to the liquid nozzles473, 475 in a manner as represented in FIG. 3. In a preferredembodiment, of the device 470 is enclosed in a casing, which is designedto collect the excess liquid from the jet 474, 476 and may be under aslight negative pressure so that any vapors can be evacuated from thesurroundings and treated.

Preparation of the Aqueous Suspension of Microcapsules

Before being deposited an aqueous suspension of the microcapsules isrequired. The microcapsules are mixed with various ingredients toproduce an aqueous suspension.

The microcapsules containing a wide variety of products encapsulatedwithin an outer shell typically polymeric in nature, in one embodimentthe encapsulated product is a scent of lavender which contains linolylacetate. Commonly the outer shell is a type of polyurethane or similarcompound previously described. The suspension in includes; themicrocapsules in aqueous suspension; a binder; and a softener typicallya silicon micro-emulsion.

The microcapsules, the binder and the softener are added in a ratio thatvaries from 35:35:30 to 48:48:4 with a preferred embodiment being45:45:10. These mixtures are then dispersed in aqueous phase in a ratioup to 25 to 30% with a preferred embodiment being between 15 and 20%.

EXAMPLES Example 1

Multifilament (pes) polyester yarn with lavender perfume microcapsules.Example 1 describes the production of a yarn that can be used to producea fabric with a lavender aroma, mainly for underwear and hosiery.

The multi-filament polyester yarn with a final decitex of 78 and 72filaments, is sprayed with a suspension composed of 85% water, 6.75% ofpolyurethane binder, 6.75% of concentrated microcapsule solution and1.5% of a silicone softener. The microcapsules used has a mean diameterof 2 microns (μm). The deposition/application process was conducted onthe false twist texturing machine.

The speed and other adjustments are standard for a DTY process with thefollowing exceptions: the speed differential between the roll 60, andthe rolls 80 of the spraying jet 70. These speeds were adjusted in orderto have minimal tension on the yarn 62 and to facilitate the opening ofthe multifilament. This opening of the multifilament produces a yarnwhich has the microcapsules within the yarn. The speed of the nip rolls100 is increased to provide more tension on the yarn in order to preventyarn sticking on the “2 bis” roll, 80. The stickiness of the yarnsderives from the fresh solution being sprayed thereon. The delivery rateof the liquid to the jet 70 is 0.139 ml/min and the air pressure is 20psi.

The yarn produced in Example 1 was knitted on a “FAK” (Fiber analysisknitter) one feed laboratory knitting machine (Lawson Hemphill Inc.)with a E22 gauge.

Example 2

Multifilament polyamide (nylon) yarn with citronella (lemon grass)perfume microcapsules.

The multi-filament nylon yarn with a final decitex of 78 and 68filaments was sprayed with a suspension composed of 85% water, 4.5% ofpolyurethane binder, 9% of concentrated microcapsule solution and 1.5%of a silicone softener. The microcapsules once again had a mean diameterof 2 microns (μm). The deposition process was conducted in the samemanner, at the same speed and settings as described in Example 1. Thedelivery rate of the liquid to the jet 70 is 0.439 ml/min and the airpressure is 30 psi. The deposition of the microcapsules was conducted ona textile winding machine.

The yarn produced was knitted and compared statistically as in Example1.

Example 3

Multifilament yarn polypropylene (pp) with lavender perfumemicrocapsules.

The multi-filament pp (polypropylene) yarn with a final decitex of 78and 68 filaments was sprayed with the solution composed of 80% water, 9%of polyurethane binder, 9% of concentrated microcapsule solution and 2%of a silicone softener. All components and conditions were maintained asin Examples 1 and 2. The delivery rate of the liquid to the jet 70 is0.781 ml/min and the air pressure is 30 psi.

The yarns produced in Example 3 were knitted in the same manner as inExamples 1 and 2.

Examples 4 and 5

Multifilament Polyamide (nylon) yarn with lavender perfumemicrocapsules.

These Examples were prepared with multi-filament polyamide (nylon) yarnwith a final decitex of 78 and 68 filaments and knit, as in thepreceding Examples.

Example 4) used a solution composed of 85% water, 4.5% of acryliccopolymer binder, 9% of concentrated microcapsule solution and 1.5% of asilicone softener and delivery rate of the liquid to the jet 70 was0.439 ml/min and the air pressure is 30 psi.

In Example 5) a solution composed of 80% water, 9% of polyurethanebinder, 9% of concentrated microcapsule solution and 2% of a siliconesoftener was used, at feed rate of the liquid to the jet 70 of 0.781ml/min and at an air pressure of 30 psi.

Example 6

A multifilament polyester (pes) yarn with a final decitex of 156 and 200filaments was used, and sprayed with the solution composed of 60% water,18% of polyurethane binder, 18% of concentrated microcapsule solutionand 4% of a silicone softener. All the process conditions weremaintained as in the preceding Examples. The delivery rate of the liquidto the jet 70 is 2.49 ml/min and the air pressure is 30 psi. Theproduced yarn was knit as in the previous Examples.

The Examples indicate that the method of deposition is effective on avariety of filaments of different materials and decitex (fineness of theyarn), through a range of deposition parameters. All five examplesshowed good deposition of microcapsules.

The embodiments of the invention described above are intended to beexemplary only. The scope of the invention is therefore intended to belimited solely by the scope of the appended claims.

1. A process for depositing additives into a yarn having multi-filamentscomprising steps of; separating the multi-filaments of the yarn intoindividual filaments while winding the yarn; injecting the additive ontothe individual filaments; and promoting the individual filaments of theyarn to close up one against the other, whereby the additives areentrapped within the multi-filaments.
 2. The process of claim 1, whereinthe additives are microcapsules in a range of diameter from 0.1 to 200μm, wherein the microcapsules comprise an outer wall and a central core.3. The process of claim 1, wherein the steps are performed on the yarnduring operation of a textile winding machine.
 4. The process of claim3, wherein the textile winding machine is selected from the groupconsisting of a winder, a texturing machine and a twister.
 5. Theprocess of claim 4, wherein the texturing machine is a false twisttexturing machine.
 6. The process of claim 4, wherein the texturingmachine is an air texturing machine.
 7. The process of claim 1, whereinseparating multi-filaments of the yarn is produced by an un-tensioningof the yarn between two shafts of a textile winding machine.
 8. Theprocess of claim 1, wherein separating of multi-filaments of the yarn isproduced by a gas jet directed at the yarn.
 9. The process according ofclaim 1, wherein injecting the additive onto the individual filaments isvia a liquid jet.
 10. The process according to claim 1, wherein the yarnis selected from the group consisting polyesters, polyamides,polypropylene, polyethylene, aramids, synthetic multifilament yarns andartificial multifilament yarns.
 11. The process according to claim 1,wherein the yarn having multi-filaments is produced by texturing aPartially Oriented Yarn (POY) or Fully Oriented Yarn (FOY).
 12. Theprocess of claim 2, wherein the central core comprises a material thatis chemically, physico-chemically or biologically active, and thematerial is selected from the group consisting of bioactive agents;drugs and pharmaceuticals; enzymes; dyes and pigments; fragrances;moisturizing agents; bleaching agents; depilatory agents; UV-blockagents; softening agents; elasticity improving agents; flame-, moth-,crease- and soil-proofing agents; water repellent agents; anti-shrinkingagents; cross-linking agents; magnetic particles; thermochromic,photochromic, electrochromic, piezorochromic, solvatechromic,carsolchromic materials; insects repellents; pesticides; staticelectricity-controlling or reducing agents; electrically conductivematerials; radar-absorbing materials; reflecting particles;heat-absorbing and/or heat-releasing phase change agents;decontamination agents; zeolites; and activated carbon; and combinationsthereof.
 13. The process of claim 2, wherein the outer wall is anatural, semi-synthetic or synthetic, high molecular weight materialsuch as gelatin; Arabic gum; agar agar; alginic acid and salts thereof;fatty acids; cetyl alcohol; collagen; chitosan; lecithins; albumin;starch; dextran; polypeptides; cellulose and chemically modifiedcellulose; polyacrylates; polyvinyl alcohol; polyvinyl pyrrolidone;polyurethane; polyolefin; polyamide; an aminoplast; polyester;polysaccharide; silicone resins; epoxy resins and formaldehyde resins.14. An apparatus for depositing microcapsules into a yarn having aplurality of filaments, the apparatus comprising; a supply spool, atake-up spool winding the yarn in a first direction between the supplyspool and the take-up spool, a means for separating the yarn at, atleast one separating point disposed between the supply spool and thetake-up spool, the means for separating the yarn thereby exposing thefilaments, and at least one nozzle proximate the separating point, theat least one nozzle injecting a liquid onto the filaments in a seconddirection transverse the first direction, the liquid having themicrocapsules suspended therein and thereby injecting the microcapsules.15. The apparatus of claim 14, wherein the at least one nozzle islocated downstream of the separating point.
 16. The apparatus of claim14, comprising; a body disposed between the two spools, the bodydefining an opening through which the yarn winds in the first directionand the at least one nozzle oriented to intersect the opening, andthereby directing the liquid having the microcapsules towards the yarn.17. The apparatus of claim 14, wherein the means of separating the yarncomprising a first and a second shaft, the shafts disposed between thesupply and the take-up spool, the first shaft winding the yarn at afirst speed and the second shaft winding the yarn from the first shaftrotating at a second speed lower than the first speed, thereby producingan un-tensioning of the yarn.
 18. The apparatus of claim 16, wherein themeans of separating the yarn comprises at least one aperture defined inthe body, the aperture connected to a supply of pressurized gas, passageof the gas through the aperture producing a gas jet directed at the yarntransverse the first direction.
 19. The apparatus of claim 18, whereinthe aperture directs the gas jet to produce an angle when intersectingthe first direction, the angle varying from perpendicular to the firstdirection, to 30° from the perpendicular to the first direction.
 20. Theapparatus of claim 18, wherein the at least one nozzle, is two nozzles.21. A multifilament yarn having a cross sectional perimeter, the yarncomprising: individual filaments interconnected together to produce theyarn; and microcapsules having a range of diameter of 0.1 to 200 μm onthe individual filaments within the perimeter of the yarn.
 22. The yarnof claim 22, wherein the microcapsules comprise an outer wall and acentral core.
 23. The yarn of claim 23, wherein central core comprises amaterial that is chemically, physico-chemically or biologically activeand the material is selected from the group consisting of bioactiveagents; drugs and pharmaceuticals; enzymes; dyes and pigments;fragrances; moisturizing agents; bleaching agents; depilatory agents;UV-block agents; softening agents; elasticity improving agents; flame-,moth-, crease- and soil-proofing agents; water repellent agents;anti-shrinking agents; cross-linking agents; magnetic particles;thermochromic, photochromic, electrochromic, piezorochromic,solvatechromic, carsolchromic materials; insects repellents; pesticides;static electricity-controlling or reducing agents; electricallyconductive materials; radar-absorbing materials; reflecting particles;heat-absorbing and/or heat-releasing phase change agents;decontamination agents; zeolites; and activated carbon; and combinationsthereof.
 24. The yarn of claim 23, wherein the yarn is selected from thegroup consisting polyesters, polyamides, polypropylene, polyethylene,aramids, synthetic multifilament yarns and artificial multifilamentyarns.